BERLIN — Klaus Florian Vogt’s voice is a phenomenon that even he has had trouble grasping. In the early days of his career, he would hear recordings of himself singing and be surprised by the timbre. He knew his tenor was bright, but outside his head it sounded even brighter.

He wasn’t the only one unsure of what to make of his voice. Lithe, polished and powerful, it continues to divide listeners. Some critics find it youthful; others, immature.

At 54, Vogt is one of the most essential performers in opera. But “there is no voice that divides fans so much,” music critic Markus Thiel wrote in a review. “‘Ethereal,’ ‘otherworldly,’ some cheer.

‘Boyish,’ ‘Wagner wish-wash,’ others complain.” These days, Vogt isn’t so surprised by his sound. “It’s continually grown closer, what my imagination is of how I want to sing and what the actual result is,” he said in an interview.

He has also accepted that his voice is not for everybody. “What I never wanted,” he said, “was to pretend to be something I’m not. That’s what’s dangerous for vocal technique and for a voice in general — when you don’t sing with your own voice.

” Vogt is a Richard Wagner specialist, with all of the composer’s major tenor roles in his repertoire as of last year, when he performed as Siegfried in the final two operas of the “Ring” cycle at the Zurich Opera House. On Wednesday, he will sing the role for the first time at the Bayreuth Festival in Germany. .